UAS Mission Planning - Bramor ppX

Introduction

This week's lab covers some of the main aspects related to UAS mission planning. Also, it goes through a demonstration of C-Astral C³P - the Bramor Mission Planner Software. The focal idea is to get a sense of understanding of how mission planning works and how pre-flight checks are integrated. Below, a variety of proper missions will be created. Click the images to enlarge.

According to the Slovenian founders, the Bramor ppX (GNSS PPK - Post Processing Kinematic) UAS is ideally suited for surveying and remote sensing applications that need a fast high-precision set of results. It gathers data down to sub-centimeter GSD level also in the absence of a grid of Ground Control Points. These are some features that make the producer C-Astral to a global market leader of Unmanned Aircraft Systems.

Figure 1: The Bramor ppX 1032 was used for this lab. Courtesy to DroneProvide.

Mission Planning Essentials – SITUATIONAL AWARENESS

·       In the Office (Before departure)

o   Know your study site

§  Cell Signal (may need to cache data)

§  Will, there be crowds (ILLEGAL)

o   Know the vegetation

o   Know the Terrain

o   Look at the map for possible Anthropogenic obstacles and features

o   Draw out several possible mission plans

§  Use geospatial data available

o   Check weather

o   Equipment:

§  Batteries Charged for all electronics

·       Departure:

o   Equipment Checklist

o   Weather Check

·       In the field

o   Field Weather (Wind Speed, Wind Direction, Temp, Dew Point)

o   Assess Vegetation

o   Assess Terrain

o   Assess if EMI issues will be present

§  Power lines

§  Underground Metal or cables

§  Power stations

o   Get Elevation of the launch site

o   Establish Units team will be working in and maintain consistency

§  Metric is best

o   Reevaluate Missions saved missions

o   Confirm cellular network connectivity

o   Integrate Field observations into pre-flight check and flight logs

Software Demonstration

The Symbols used in C-Astral C³P:
o Home
o T – Takeoff Point
o R – Rally Point
o L – Landing Point

The Takeoff Point is the point where the Bramor UAV will be when it reaches the height it is set to. Hence, the takeoff point is not the ground spot but the Home point. The Landing point is the point where the Bramor UAV touches the ground and the Rally point is the point where the UAV initiates the descent. It is crucial to make sure there is nothing the Bramor UAV may hit between the Rally point and the landing point.


Mission 1: Bislett Stadium

It was decided for the initial flying mission to take place in Oslo and produce images over the famous stadium of Bislett.

Figure 2: The area of interest - Oslo, Norway.

Figure 3: The settings used for this flight. The GSD relates to the sensor on the UAV.

City terrains are not the best location to use fixed winged UAVs, like Bramor, since there will be takeoff and landing issues. However, the first mission is only a simulation in order to learn the UAS software. The quality of map data in the Nordic countries is updated and in terms of details, it is as good as it gets, hence we expect the z-value for buildings and trees to be correct. It is important to double check on-site. In the real world, there are also regulatory issues that one needs to be aware of, especially for fixed winged UAVs. Again, this is a strictly hypothetical mission.

Figure 4: An overview of the area of interest.

Figure 5: Home, Takeoff, Rally point, and landing point.

Figure 6: The waypoints chosen over Bislett Stadion.

Figure 7: Sensor calibration.

Figure 8: After the Sensor calibration and the upload of waypoints are done, the actual flight can commence by choosing to navigate.

Figure 9: After the mission is carried out, a flight summary will show up with certain data. 

Figure 10: The right corner reveals that 234 images were taken, which will be able to look at through this application.

Figure 11: The UAS mission planning is possible to export to Google Earth, here 3D view.

Figure 12: The flight path

Figure 13: The taken photos with its corresponding overlapping.

Figure 14: A so-called corridor mission along with a linear feature, in this instance a road.

Mission 2: Bramor Test Field

The second flying mission takes place in Slovenia, where the producer has its own test field. Learning the software is much about playing around with some of the settings, like the image below, where the altitude settings were tested. Since the Bramor Test Field itself (nearby trees excluded) does not have a high variance in elevation, Absolute altitude could be used.

Figure 15: Absolute mode is used during a mission that does not have a high variance in elevation.

Figure 16: The higher the altitude, the worse Ground Sample Distance. Here the altitude is set to 590 meters and the GSD is 7.6 cm per pixel.

Figure 17: The bigger the value of the image GSD, the lower the spatial resolution of the image and the less visible details. Thus, with this mission settings like this, 74 meters altitude, the GSD is greatly improved, 1 cm per pixel.

Figure 18: Absolute altitude works badly when flying over trees.....

Figure 19: ..... In red is the area of which the UAV will hit the trees...

Figure 20: ... Therefore, the Altitude mode is changed to Relative, since that is radically safer to fly within areas of high altitude uncertainty. Here the Altitude was set to 104 meters. Is that enough here?

Figure 21: Well, no. There are still some areas that will intervene with the UAV. An altitude of 125 meters should be enough.

Figure 22: After the mission planning is set, it is possible to export the mission to 3D and watch it through Google Earth.

Mission 3: County Amphitheatre Park in West Lafayette

Figure 23: By looking at the map, it is clear that variance in height exists here. Therefore it is more convenient and much more safe to go for the relative altitude.

Figure 24: Altitude mode set to Relative.

Figure 25: The wind was set to the southwest. When landing the UAV the flight planner will set the Bramor to fly into the wind and be sure it will not have a tailwind. Also, important to make sure there are no obstacles between the Rally point and the landing point.

Mission 4: Winter Park, Colorado

In places with mountainous terrain are especially hard to plan out missions, take Winter Park in Colorado for instance. It is not the ordinary hazards like birds, air traffic, telephone poles, and radio towers to be aware of but also a lot of trees, and in this case, the high altitude and the pressure that comes along. For this mission, absolute altitude was used here as this applies even more in these mountains than it did for the Amphitheatre Park in West Lafayette.

Figure 26: Wind speed was set to 4 m/s. Landing point was chosen based on where the wind came from. However, after I changed the wind direction 180 degrees, I forgot to change the Takeoff point as well, which should be in the other direction. It is critical that UAVs take-off into the wind and not like the image displays. In the software exists an option to measure the distance of areas of interest too. Not displayed here though.

Overview of the preflight check on the Bramor UAV

Figure 27: Starting off by going through the equipment checklist together with another person or co-pilot.

Figure 28: The software to instruct where the UAV will fly its mission. Both possible to upload waypoints and to create the mission itself on the tablet.

Figure 29: An earlier mission over Purdue's Airport. Doublecheck that batteries are charged. Also, check the weather before moving out.

Figure 30: The body of the Bramor UAV.

Figure 31: The Sony sensor

Figure 32: The sensor from the underside.

Figure 33: Since the wind came in from Southwest, we wanted to launch the Bramor UAV into the wind. Absolutely crucial.

Figure 34: Professor Hupy checks the speed of the wind.

Figure 35: Dr. Hupy demonstrates how the catapult works.

Figure 36: Combining the wings with the body.

Figure 37: Important step is to fix the wings with tape.

Figure 38: The Bramor UAV is set together

Figure 39: When using a fixed UAV, like Bramor, it is important to have both a pilot and a co-pilot(s) that collaborate well together. Look at these smooth guys working together.

Figure 40: Next step, we put in the batteries one at a time.

Figure 41: The UAV batteries were labeled.

Figure 42: Put the wires from the two batteries into a Y-connector.

Figure 43: Loading the parachute into the UAV.

Figure 44: It is important to check the cell signal and look for possible obstacles when planning the mission.

Figure 45: Setting up the catapult

Figure 46: Catapult ready for the UAV.

Figure 47: Dr. Hupy finalizes the process after the Bramor UAV is placed at the catapult.

Figure 48: Be careful, not to hit trees.

Figure 49: Like mentioned before, it is crucial to launch the UAV into the wind.

Figure 50: Catapulting the Bramor. Courtesy to Evan Hockridge.

Figure 51: Popping the parachute. Courtesy to Evan Hockridge.

Conclusion

I hope this blog post was informative and at least some of the readers got some more knowledge and understanding of the importance of mission planning and pre-flight checks.

For UAVs like the fixed winged Bramor (that is intensely autopilot centric) the pre-flight check is of utmost importance since there are so many steps that could go wrong. The mission planning permits efficient use of the UAV and, if used properly, time could be saved.